Thanks Iluvrevs

Update:

http://www.flickr.com/photos/9krpmrx8/6595046221/

I have this as well in case you don't get them

http://www.flickr.com/photos/9krpmrx8/4390637228/http://www.flickr.com/photos/9krpmrx8/5405404751/http://www.flickr.com/photos/9krpmrx8/5407309753/

All good, did come across those and collected the results.

Im sooooooo confused on what oil to use after reading this thread... I have 87k on my car... not sure its the original motor as i got the car with 84k I need an oil change what oil should i use? also i live at 5000ft. alt.

I think the conclusion to draw from the data is that damn near any oil will do, leaning toward oils that retain their viscosity. Some of these oils definitely don't keep up the viscosity.

To me I think that means overpriced synthetics or cheap diesel oil. The 15W-40 cheap diesel oil works for me.

I sent in a sample 2 days before Christmas and added mail confirmation; apparently it's still sitting in the post office. :(

If your car is out of warranty or you are not worried about the warranty, then many people recommend an XXw40 oil. I have used Castrol 5w30 with good results and am still using a 5w30 because I am under warranty; several people on here use 5w40 or 0w40 synthetic. A lot depends on how you drive (street/track/stop and go) and environment (heat/humidity) and mods to your engine.

Most agree that the factory recommended 5w20 dino is too weak to provide proper lubrication/protection. My local Mazda dealer uses 5w30 Castrol so I figure they would have a hard time turning down a warranty claim for using 5w30.

The MOST IMPORTANT thing you can do is use a good quality oil (dino or synthetic) and change every 3000 to 5000 miles while checking often and keeping it topped up. Some poeple change their oil more often, few would recommend a greater than 5000 mile OCI althought the manual says up to 7,500...:dunno:

I use 20w50 in my 1979 12A motor.

Looking at the analysis I did and had posted here via an Excel pivot table its not real clear what factor oil plays in our engines. However, in manipulating the pivot there are additional trends that may be meaningful but as with this view they are still not obvious. If anyone wants the Excel version PM me your email addy and I can forward.

Keep in mind that even among trbology experts there are varying opinions as to whether or not a UOA provides any indication of engine versus simple the condition of the oil. So with that following are the patterns I see.

There appears to be some minimal reduction in Chrome and Copper occurrence in the samples that seems to relate to the use of 10w and 15w40.

There appears to be some minimal reduction in Iron occurrence with the use of 5w20 and 10w30.

And oddly enough there seems to be more significant reduction of the occurrence of Aluminum with the use of 5w20 and 15w40.

These 3 observations are adjusted for mileage on the OCI.

Then when I manipulate the pivot to account for ZDDP I see NO indication that the occurrence of any potential wear metals is impacted by additional quantities of the additive.

Manipulation again for Molybdenum and Boron, both of which serve as antiwear additives I still see no indication that there is benefit to higher quantities of these additives.

One pattern that sticks clearly out from additional manipulation of the pivot is the occurrence of potential wear metals increasing as the engine accumulates mileage beyond 50,000 or so. This is clear, but not still not terribly clear. Maybe this is from bearing and gear wear causing more movement of the rotor? I’m not knowledgeable enough to say.

Another thought I have is that we aren’t interpreting these UOAs correctly. We have a much smaller engine than the piston type possibly meaning the acceptable potential wear numbers should be adjusted down accordingly.

My final thought is that while the variations in metal occurrence between oil grades in minimal the slight advantage to 10w40 and 15w40 may support what some of the engine builders here have said with regard to viscosity and engine wear. To be more comfortable with this logic we’d need some 50wt UOAs and preferably 20w50.

Revs, try the numbers around measured viscosity in the UOA rather than claimed initial viscosity.

Update from Iluvrevs

http://www.flickr.com/photos/9krpmrx8/6685858517/

Coming shortly, stand by.

Sorry man, got super busy yesterday afternoon.

http://www.flickr.com/photos/9krpmrx8/6690178673/

i thought this would be good to include in this discussion:

Metal Tests

Some of the metals tested for and usually included in analysis of an oil sample and their potential sources are:

Aluminum (Al): Thrust washers, bearings and pistons are made of this metal. High readings can be from piston skirt scuffing, excessive ring groove wear, broken thrust washers, etc.

Boron, Magnesium, Calcium, Barium, Phosphorous, and Zinc: These metals are normally from the lubricating oil additive package. They involve detergents, dispersants, extreme-pressure additives, etc.

Chromium (CR): Normally associated with piston rings. High levels can be caused by dirt coming through the air intake or broken rings.

Copper (CU), Tin: These metals are normally from bearings or bushings and valve guides. Oil coolers also can contribute to copper readings along with some oil additives. In a new engine these results will normally be high during break-in, but will decline in a few hundred hours.

Iron (Fe): This can come from many places in the engine such as liners, camshafts, crankshaft, valve train, timing gears, etc.

Lead (Pb): Use of regular gasoline will cause very high test results. Also associated with bearing wear, but fuel source (leaded gasoline) and sampling contamination (use of galvanized containers for sampling) are critical in interpreting this metal.

Silicon (Si): High readings generally indicate dirt or fine sand contamination from a leaking air intake system. This would act as an abrasive, causing excessive wear. Silicon is also used as a anti-foam agent in some oils.
Sodium (Na): High readings of this metal normally are associated with a coolant leak.

Now remember we have twin oil coolers and those big old stationary gears that chew the oil up--lol. We have a huge exposure for the oil in and around the rotors---so a rotary engines percentages will be different than a recips. I am not sure how they compare samples.
Heck its looks like the 30 wgts are doing pretty good.
I have heard from a few of the possibility that the new shaped side seals can't handle the heavier viscositys the 40/50 wgt stuff? no proof offered yet.

2nd Pivot
 

Yay in that it wasn't lost in the mail afterall, boo in that the chromium won't go away. :(

http://dl.dropbox.com/u/25219728/rx8uoa.JPG

FWIW, I have switched to Valvoline 5w30 full synthetic after this oil change (was previously using Valvoline 5w30 conventional).

Ferret, changing from dino to sythetic will not likely make any difference. I think you need to step up the viscosity.

And would somebody explain to me how chromium from the apex seals gets into the oil when the apex seals contain no chromium? And any chromium they scrape off the housings is going right out the exhaust port. The only "action" you could take is rebuild the engine (or better, switch to a higher viscosity!). Methinks Blackstone don't know der Wankel...

I agree, and plan to do that once winter is over with ... or should I just do it now? :dunno:

If you are worried about the cold go with Mobil1 0W-40.

After reading all the goods about it (from you ;) ) I actually ordered 2 cases of the stuff instead of my usual royal purple regimen . Will post some UOA's of my runs with it.

Meh. I run 15W40 year-round now. No trouble starting in bitter cold (and I have original less-powerful starter). I just keep the revs and loads down by driving gently until the temps come up.

Oh, and I have the radiator almost completely blocked once the temps drop below 40. Otherwise I can't get above 175 and more like 160-165 on sub-freezing days. With the rad blocked it goes up to 180-185 and just sits there. Important for keeping viscosity up and moisture out. I don't get any mousse under my filler cap.

I ran some 10W-40 dino oil during break in and I saw no real difference in oil pressure or how the car ran when I switched to my normal 0W-40 last weekend. But, the 0W-40 has performed well for me over the years so I'll stick with it. I'll probably do my first UOA on this engine in 2,000 miles.

I think I will, thanks! Do you use that year-round?

Yes, but it stays warm here year round for the most part.

Gotta hand to the Valvoline for holding viscosity in grade. But, not doing a thing for wear prevention.

I actually did yet another analysis if you guys are interested. M10w40 actually showes as the best choice so far, though it would help to have more samples.

Wankle, how long have you been running 15w40 in the cold? Also, whats your avg cold and max?

I'll have a UOA soon enough and REDRX3RX8 should have a sample coming up I would think as well.

Mobil 1 0w40 also has moly and boron for antiwear which might slow down that chrom which is coming from those agressive staionary gears.

Your uoa looks good with very low fuel.

so just get some 0w40, and you'll have 3 improvements: Thicker, Moly, and boron. :)

This oil was developed for hot hard to lube German cars, so yes, this oil holds up to extreme engine use.

Everyone gets thrown off by that 0w. It's not a thin oil. I just doesn't thicken much when cooling.

maskedferret how is your oil consumption? You might have clogged OMP nozzle or two.

I think at most it's ever been is maybe 1.5 quarts per 3000 miles. Seems to have been slowly diminishing ... just under 1 per 3000 by now. The thought has crossed my mind. I just don't look forward to taking out the UIM to check.

before you do that I would run some seafoam trough your OMP. that might do the trick.
more info here: https://www.rx8club.com/series-i-tech-garage-22/optional-ports-seafoam-omp-nozzle-cleaning-217177/

My uoa had approx 4 ppm chrome, and my 8 only uses about 1 qt in 4k miles.

IMO that lubing the apex seals won't change your uoa, just save the compression.

You should already be putting in about 7 or 8 oz. premix per fillup (approx 12 gals).

I'll change my oil before the next track day in a few months, and the miles on it will be approx 5500 miles, but my uoa at 23k miles showed no water, and almost no dirt or excess fuel.

therefore, I'll get uoa every other oil change just for fun, not this oil change.

And you live and drive in the dustiest environment known to man so that just amazes me. But then again keeping a clean air filter at all times helps that I would think.

Did you post those up here? I thought the only 0w40 UOAs were from 9K.

He is a traveling man, his username when he is stateside is REDRX3RX8. I have posted his 0W-40 results.

Here are my UOAs.
1st sample was with Shell Rotella 5w-40 and whatever was in the car when I bought it.

2nd and 3rd sample are same batch of redline 5w-30. 2nd sample had 2 track days on it and 3rd sample(same oil) had 6 track days on it.

I also had a crack that was letting unfiltered air in (hence higher silicone) on the pvc fitting connecting the crankcase vent to the intake.

I say oil held up very well given the track days and coolant in the oil.

alumaseal took care of the coolant leak for now.

https://www.rx8club.com/picture.php?...ictureid=30257

My email played dead so, I'm on my laptop in Java, and I don't mean coffee.

I'm REDRX3RX8, and 9krpmrx8 edited and posted my uoa's for me.

I started talking to him from this uoa thread where I saw he was using Mobil 1 0w40, my favorite oil.

I'm not sure that Mobil 1 0w40 is the best oil in the world for the 8, but I don't see anything better.

These uoa's don't necessarily find good oils, but they can find bad engines, and sometimes oils that aren't working like the high chrom from MaskedFerret.

I still have the original air filter, and had almost no dirt at 23k miles!!!

And you saw the cup full of red sand that we threw out of the AC air filter!!:shocking:

Was wondering if anyone of you has try this before?

I was walking in walmart looking for 5w-40, but instead bump into this brand.

It intrigues me to read the following:
A good straight mineral engine lubricant refined by modern methods....

but it's non-detergent... what does that means? It is also SAE30 which means our rotatory is suitable to use it right?

This is usually used for compressors and the like
Dont want to use in a combustion engine

Do not use non-detergent oil in a modern engine. (i.e. one made after your parents were born.)

A guy with a nice rebuild 55Chevy came through our service station way back in 1969, and bragged about how clean his oil was with Non Detergent SAE30.

As I checked his oil level I did see that it was somewhat clear and golden, but we were fuel distributors, and at 17, I even knew that: "Yeah, the oil is pretty, but all the dirt from your air is glopping all over your valve train."

In later years, I had customers asking for mo SAE30 instead of turbine oil because it could handle high heat of compressors.

Jeez you Americans love wasting your money on UOA's...;)

In the end you get all this info and what do you do about it???...most from what I read do little or nothing...so what for?

In the end if your coolant is getting low and you can't find a leak with a "normal" pressure tester then odds are you have coolant entry into your Rotary Engine....needs a rebuild.

If you have excess chrome in your UOA it is either Apex Seals/Corner Seals wearing off the chrome on your Rotor Housings or at worse worn Rotor Bearings damaging the Eccentric Shaft journals...Again what are you going to do about it??...Premixing is too late to change flaking or wearing RH chrome....again a rebuild.

You could possibly get YEARS of service/miles out of your engine BEFORE a rebuild is needed, so you let a high chrome UOA worry you to death for a thousand days..when you are better off NOT knowing. :)

None of this analysis will stop your engine crapping itself....in the end..:)

^Got up on the wrong side of bed, eh?

Your point is mostly right, but we have to find something to waste our money on, since we don't drink as much Foster's as you guys down there! ;)

I agree uao's are useless once you have decided what oil to run. Unless you want to go to an extended oil change interval or trying to diagnose a problem--like how well is that air filter actually working.
Its a tool just to use selectively.
We can discuss it over a couple of those Fosters!

Well with my coolant seal failure I was not seeing a loss of coolant or smoke from the exhaust and diagnosing the problem was actually pretty difficult. The UOA confirmed the presence of coolant. If I had not been in the habit of testing my oil, I probably would have wasted more time blaming my ignition coils for the misfires, chasing down exhaust leaks, and trying to trouble shoot even more.

I mean eventually it would have gotten bad enough and I would have started to get smoke in the exhaust and a noticeable amount of coolant loss but the UOA told me what i needed to know and I didn't have to pull apart the engine myself to find out :)

Besides, it's only $20.00 a couple of times a year (or less if you are 40w8/REDRX3RX8).

right on--use it to diagnose a problem.

I do UOAs because I'm a data geek. It's cheap fun. :)

for me (at least), knowing the weariness is how you prevent and take measures to extend the longevity of the engine.

I mean.. just take this for example, E.g. your health report, if you regularly go for health check-ups to 'detect' or make queries to your body -- it's good to find out if you have any problem vs. someday you realize you have a "lump" (out of no where); with early detection/ prevention, you can easily fight "cancer" at a way earlier stage, which give you a better chance to make a full recovery. or whatever high cholesterol (i.e. too much chrome), diabetes, and etc.

Yep, take my coolant seal problem for example. If you catch a problem like that early you can save major parts from being ruined and in turn that will save you a ton during the rebuild process.

I like the "cheap fun" idea. Not much of that left anymore.
Wild weekend--buy lotto ticket and get my uoa report in!
cost $21. Heck cant even go to a stupid movie/popcorn/coke for that anymore.

Better to be prepared than to be caught with our pants down around our ankles and no money for a rebuild.

I do UOA's to compare my "new" engine results with whatever results I get in the future. Any skewed results and I know that I should probably start putting aside a bit more money in the "just-in-case" tank.